Adaptable drawing mechanism or device for producing strands by continuous casting

ABSTRACT

A drawing mechanism for the drawing of strands consisting of conveying rollers and press rollers all of which being variable, laterally, on their drive shafts and alignment rails.

United States Patent Heribert Krall Wurzburg, Germany Appl. No. 717,648

Filed Apr. 1,1968

Patented Mar. 2, 1971 Assignee Technica-Guss GmbH Wurzburg, Germany Apr. 5, 1967 Germany Inventor Priority ADAPTABLE DRAWING MECHANISM OR DEVICE FOR PRODUCING STRANDS BY CONTINUOUS CASTING 2 Claims, 5 Drawing Figs.

U.S. Cl... 164/282 1nt.Cl 822d 11/12 Field of Search 16 8 [56] References Cited UN1TED STATES PATENTS 3,347,308 10/1967 Saunders FOREIGN PATENTS 580,262 7/1959 Canada 817,637 lO/l951 Germany. 801,819 9/1958 Great Britain 121,913 a 1959 U.S.S.R.

Primary Examiner-J. Spencer Overholser Assistant Examiner-R. Spencer Annear Attorney-Jones and Lockwood ABSTRACT: A drawing mechanism for the drawing of strands consisting of conveying rollers and press rollers all of which being variable, laterally, on their drive shafts and alignment rails.

PAIENTED'HAR 2197: 3565955 SHEEI UF 3 Fig.3 /e

BACKGROUND oF THE INVENTION The invention relates to a drawing mechanism for the continuous or intermittent drawing of strands of metallic stock in continuous casting with at least one conveying system for each strand, consisting of a conveying roller with its driving shaft and press roller opposite to it with pressing device. a

The casting process serves for the continuous casting of molten metal in moulds open at both ends, whereby the solidifying metal within the mould is drawn out in a solid state, and of the shape relative to the configuration of the mould. The resultant shape, designated as strand, is drawn by various conveying rollers and gripper systems. The direction of force ap plied to draw the strand has to be applied opposite to the casting axis with precision and uniformity.

Many continuous casting machines are working with vertical molds, i.e. in a'vertical casting direction. This requires a considerable overall height of the corresponding plants or, shortly after leaving the mold and a short cooling interval, the strand has to be bent off and cooled in horizontal direction and cut to lengths. A casting process with a horizontal casting direction and horizontal moulds is also used to a lesser extent.

The horizontal continuous casting process is of special im portance in plants where bending from the vertical casting direction to the horizontal working direction, is not possible, in other words, when producing various metal sections that cannot be hot or cold formed.

As already indicated, the drawing of the strands in horizontal or vertical casting is effected by means of conveying rollers or by means of gripper systems. The conveying rollers are driven, and in most cases, the counterpressure is exerted by press rollerswhich are pressurized pneumatically, hydraulically, or mechanically, or by other suitable means i.e. they are pressed onto the casting strand.

The known casting plants accordingto the continuous casting principle are working either with one single strand or more strands, i.e. oneplant is suitable for casting one or several strands respectively at the same time and side by side. In the case of the multistrand casting plant, the strands are flush side by side or clustered; e.g. in the four-strand process 2 X 2 strands are arranged in-a square.

1 With the known continuouscasting plants an alteration of the production, i.e. an alteration of the section of the drawn material, is not possible without recourse to major conversion work. Without mentioning that of course the mold has to be replaced when changing the production to another section, the entire drawing device cannot be readapted. Owing to this, sections with cross dimensions of only very small differences can be produced on one plant. Plants for universal use which include a production from minimum strand diameters up to larger sections, such as iron slabs and blocks of considerable diameter or sections respectively without requiring a time consuming conversion are not known so far. I

Especially when casting melts of metal which cannot be formed any more, i.e. the desired section of which has to be formed by rolling, drawing, forging, or the like, a continuous casting machine is of particular significance which facilitates a conversion when changing the manufacturing programme.

SUMMARY OF THE INVENTION from one section to a completely different section without any major expenditure of equipment and work. Not only a conversion to various sections of the strands is possible with this device, but also it is possible in a very simple and reliable manner to convert in a very short time e.g. from a four-strand to a two'strand 0r single-strand operation. This, of course, applies also for an odd number of strands.

Another advaniage of this device is that one independently driven drawing mechanism is provided for each strand. When the entire plant is producing the maximum number of strands, each stand can be drawn by itself, and independent of the other strands. On the other hand, with a reduced number of strands, it is possible to utilize without any difficult changes the conveying devices now remaining regarding the number of strands. Thus, it is possible, when using the device according to the invention, to operate a five-strand plant in such a way that in the one extreme case five sttands are driven and drawn differently and in the other extreme case one single strand. which is drawn by several, or all conveying devices of the plant, if need be. This special case applies particularly when casting heavy blocks. The mechanical driving power of the individual conveying devices can be kept lower than necessary, if a heavy block had to be drawn by a single conveying device.

Consequently, the device according to the invention is extremely variable, viz. with regard to the strands to be drawn, the independent conveying speed of the individual strands and the efficiency and power requirements for conveying cast strands of large dimensions and weight.

The invention relates to a device for the continuous or intermittent drawing of metal strands in the continuous casting process with at least one conveying system for each strand, consisting of a conveying roller with its driving shaft and an associated press roller with a proper pressing device.

One of the features of the invention for attaining this object is that for each strand at least one independently driven conveying roller is provided, and the conveying rollers on their driving shafts are arranged in series in the direction of the casting axis as well as the press rollers with their driving devices are arranged across the casting axis and are displaceable.

For a more complete understanding of the invention, reference is had to the drawings in which:

FIG. 1 shows schematically in plan view a four-strand method of operation with four driving shafts each having a conveying system arranged in series in the casting direction from left to right; v

FIG. lashows schematically in plan view a two strand method of operation where two conveying'systems draw each strand from left to right;

FIG. lb shows schematically in plan view a single-strand method of operation with four conveying systems spaced along the casting axially from left to right;

FIG. 2 shows a vertical crosssectional view of the conveying system working on one strand in the four-strand operation according to FIG. 1; and

FIG. 3 shows a diagrammatic sectional view along line AA of FIG. 2.

With the device according to the invention, one conveying system consists thus of .one conveying roller on its driving shaft, and at least one press roller with its pressing devices;

'each being independently driven. Each conveying system is adjustable as a whole. Supposing, for example, that the plant has been designed for a maximum of four strands, then at least four conveying systems have to be provided, whereby each conveying system handles one strand, and is displaceable across the casting direction on its driving shaft. In order to avoid a mutual hinderance of the conveying systems of adjacent continuously cast strands, the driving shafts of the conveying rollers as well as the support and alignment rails of the pressing devices for adjusting the press rollers are arranged in a staggered series in the casting direction. Thus a four-strand plant, for example, can be set to the following working program: Four. thin sections whereby each strand is drawn by one conveying system;

Two large sections whereby two of the four existing conveying systems each draw the two strands by displacement on their driving rolls and pressure rolls respectively. If the size of the strand is not too large and the drawing device is dimensioned correspondingly, then it is also possible to draw with only one conveying system in two-strand casing; and

One strand of large dimension is cast and now drawn by one up to four conveying systems. The conveying systems act on the strand in line ahead of each other in the casting direction.

Logically, for example, a plant with a maximum capacity of six strands can operate with six, three, two strands or one strand. The conveying systems act according to the above specification. As a matter of fact the plant can also be operated asymmetrically. Keeping to the example of a fourstrand plant, it is possible to produce two thin sections with one conveying system each and to draw one larger section with the remaining two conveying systems.

The only prerequisite for the device according to the invention is that the cast strands are arranged side by side extending in one plane. The device according to the invention is suitable for vertical as well as for horizontal casting. The conveying systems can be driven continuously, ie at a uniform speed without interruption or also intermittently. A complete adaption to the specific casting process, and the subsequent cooling of the strand until solidification to such an extent that the strand can be gripped by the rollers is possible without any dif ficulties and without any major expensive changes.

A further example of application of the device, according to the invention is the significance of the conveying systems driven independently of one another. If, for example, a fourstrand plant is used working with two thin strands driven by one conveying system each, and one larger strand driven by two conveying systems, then it is, of course, desirable that the drawing speed of the thin strands, and the thick strand be governed by the time of solidification and the heat dissipation in the cooling interval, and not to the contrary that the casting process has to be adjusted to the rate of drawing. By means of these independently driven conveying rollers, different sections can also be produced simultaneously with a multistrand plant. As is well known, the drawing speed of the strand will depend to a certain degree on the cross section of the strand and directly to the rate of the heat loss in the mold and after leaving the mold. Thus thedevic'e according to the invention leads to a simplification of the casting process itself, due to the possible variable drawing rates for each independent strand.

The special design, mounting, mechanical function, dri e, etc. of the components of the conveying system is essentially constructed in the known way. The driving shafts for the conveying rollers, for example, are set in motion via bevel gears for the power transmission from an electric motor to the driving shaft. The conveying rollers themselves may have every usual shape, i.e. from cylindrical to double-conical, whereby the double cone matches up with the section of the strand. The conveying roller itself is mounted on the driving shaft and can be slid laterally along the shaft, and can be fixed in the desired position in the known way.

' The press rollers can be used which are preferably cylindrical. Frequently, they are mounted in a bracket; as usually the contact pressure is applied by a pressing device-cg. hydraulically, pneumatically or by electric motor. The pressing device and possibly also the press rollers themselves are supported on alignment rails so that they are adjustable across the casting axis in relation to the conveying rollers. They are fixed in the desired position in the usual way.

The drive according to the invention will now by explained in more details by the following description with reference to a four-strand plant with some of its applications.

The four strands S1 to S4 according to FIG. 1 are arranged in one plane. The four driving shafts At to Ad for the four conveying systems T1 to T4 are arranged in series in casting direction, each stands being drawn by one conveying system.

FlG. 1a shows the two-strand method of operation, whereby the two conveying systems T1 and T2 draw strand SA and two conveying systems T3 and T4 draw strand SB. Contrary to their position in FIG. 1 all four conveying systems are adjusted to the casting axis by a displacement along their shafts across the casting direction.

FiG. 1b shows a single-strand operation, whereby in this special case all four conveying systems Ti to T4 are centered on the casting axle by a corresponding adjustment across the casting direction. Of course, in case of single-strand operation all four conveying systems must not in all cases by used for drawing a strand. 7

From FIGS. 2 and 3 can be seen that in a frame 1, 1' the shaft Al is mounted in the bearings Z, 2' and can be rotated by the driving unit (not shown). On the shaft A1 a double-cone conveying roller 3 is mounted which draws the strand S1. The press roller 4 is pivoted in fork 5 and is pressed onto the strand by the pressing device 6 which can be displaced across the casting direction. For example, the displacement of the pressing device 6 can be effected via the alignment rails 7, 7 mounted to frame 1, 1 means of the corresponding fixing means.

FIG. 3 shows the form of construction according to FIG. 2 in the section A-A. The conveying systems T shown in FlGS. 1, 1a, lb and 2 comprise rollers 3 and d and their related equipment.

Although my invention has been illustrated and described with reference to the preferred embodiment thereof, 1 wish to have it understood that it is in no way limited to the details of such embodiment but is capable of numerous modifications within the scope of the appended claims.

I claim:

l. Mechanism for the simultaneous drawing of several strands of metallic stock in continuous casting with at least one independently driven conveying system for each strand, consisting ofa conveying roller with its drive shaft on which it is slidably mounted and press roller means mounted opposite to it for sliding movement on a mounting shaft, in which the conveying systems associated with each strand are arranged one behind the other in the direction of the casting and in which the conveying rollers and press rollers of each conveying system are movable in the direction oftheir shafts to a conveying roller position of each stand, said drive and mounting shafts extending crosswise the several strands.

2. A drawing mechanism for the continuous or intermittent drawing of strands of metallic stock in continuous casting havat least one conveying system for each strand consisting of a conveying roller with its driving shaft and a press roller opposite to the conveying roller and having means for applying a pressure thereto;

said conveying roller having independent drive means;

said conveying rollers being mounted on driving shafts and arranged in series and spaced from each other in the direction of the casting axis;

said press rollers and their pressing devices also being arranged in series and spaced from each other in the direction of the casting axis;

said conveying rollers being shiftable laterally from one strand to another strand on their drive shafts which extend transverse to the direction of the drawing of the strands; and

said press rollers and their pressing devices being mounted on rails extending transverse to the direction of the drawing of the strands and shiftahle laterally from one strand to another strand to a position for cooperation with their respective conveying roller. 

1. Mechanism for the simultaneous drawing of several strands of metallic stock in continuous casting with at least one independently driven conveying system for each strand, consisting of a conveying roller with its drive shaft on which it is slidably mounted and press roller means mounted opposite to it for sliding movement on a mounting shaft, in which the conveying systems associated with each strand are arranged one behind the other in the direction of the casting and in which the conveying rollers and press rollers of each conveying system are movable in the direction of their shafts to a conveying roller position of each stand, said drive and mounting shafts extending crosswise the several strands.
 2. A drawing mechanism for the continuous or intermittent drawing of strands of metallic stock in continuous casting having; at least one conveying system for each strand consisting of a conveying roller with its driving shaft and a press roller opposite to the conveying roller and having means for applying a pressure thereto; said conveying roller having independent drive means; said conveying rollers being mounted on driving shafts and arranged in series and spaced from eacH other in the direction of the casting axis; said press rollers and their pressing devices also being arranged in series and spaced from each other in the direction of the casting axis; said conveying rollers being shiftable laterally from one strand to another strand on their drive shafts which extend transverse to the direction of the drawing of the strands; and said press rollers and their pressing devices being mounted on rails extending transverse to the direction of the drawing of the strands and shiftable laterally from one strand to another strand to a position for cooperation with their respective conveying roller. 